• 대한의생명과학회지
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• 제29권4호
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• pp.371-375
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• 2023

Natural killer (NK) cells are innate immune cells and play important roles as the first immune cells to recognize and kill cancer. In patients with advanced and terminal cancer, NK cells are often inactivated, suggesting that NK cells may play important roles in cancer treatment. In particular, the proportion of NK cells among immune cells infiltrating tumor tissues is often low, which suggests that NK cells do not survive in tumor microenvironment (TME). In order to overcome these hurdles of NK cells in cancer treatment, it is critical to develop strategies that enhance the proliferation and cytolytic activity of NK cells. We applied Vemurafenib to NK cells and measured the degree of NK cell proliferation and functional activation. We obtained unexpected results of increased NK cell numbers and anti-tumor activity after Vemurafenib treatment. Although further investigation is required to uncover the detailed mechanisms, our results suggest that Vemurafenib is a promising candidate to increase the efficacy of cancer immunotherapy using NK cells.

• 대한의생명과학회지
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• 제29권4호
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• pp.382-385
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• 2023

NK (Natural killer) cells are innate immune cells and play important roles as the first immune cells to act when cancer occurs. In many cancer patients, NK cells can be seen to be inactivated, suggesting that NK cells are important in cancer treatment. In order to overcome the disadvantages of NK cells in cancer treatment, it is critical to develop strategies that enhance the proliferation and cytolytic function of NK cells. We applied niclosamide to measure the degree of NK cell activation, and obtained unexpected results of increased NK cell numbers and anti-tumor activity. Although further investigation is required to uncover the detailed mechanisms, our results suggest that Niclosamide is a promising candidate to increase the efficacy of cancer immunotherapy using NK cells.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.265-271
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• 2014

Interleukin-7 (IL-7) is a potent anti-apoptotic cytokine that enhances immune effector cell functions and is essential for lymphocyte survival. While it known to induce differentiation and proliferation in some haematological malignancies, including certain types of leukaemias and lymphomas, little is known about its role in solid tumours, including breast cancer. In the current study, we investigated whether IL-7 could enhance the in vivo antitumor activity of tumor-reactive $CD8^+$ T cells with induction of IFN-${\gamma}$ in a murine breast cancer model. Human IL-7 cDNA was constructed into the eukaryotic expression plasmid pcDNA3.1, and then the recombinational pcDNA3.1-IL-7 was intratumorally injected in the TM40D BALB/C mouse graft model. Serum and intracellular IFN-${\gamma}$ levels were measured by ELISA and flow cytometry, respectively. $CD8^+$ T cell-mediated cytotoxicity was analyzed using the MTT method. Our results showed that IL-7 administration significantly inhibited tumor growth from day 15 after direct intratumoral injection of pcDNA3.1-IL-7. The anti-tumor effect correlated with a marked increase in the level of IFN-${\gamma}$ and breast cancer cells-specific CTL cytotoxicity. In vitro cytotoxicity assays showed that IL-7-treatment could augment cytolytic activity of $CD8^+$ T cells from tumor bearing mice, while anti-IFN-${\gamma}$ blocked the function of $CD8^+$ T cells, suggesting that IFN-${\gamma}$ mediated the cytolytic activity of $CD8^+$ T cells. Furthermore, in vivo neutralization of $CD8^+$ T lymphocytes by CD8 antibodies reversed the antitumor benefit of IL-7. Thus, we demonstrated that IL-7 exerts anti-tumor activity mainly through activating $CD8^+$ T cells and stimulating them to secrete IFN-${\gamma}$ in a murine breast tumor model. Based on these results, our study points to a potential novel way to treat breast cancer and may have important implications for clinical immunotherapy.

• 대한수의학회지
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• 제39권5호
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• pp.1028-1032
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• 1999

Alpha toxin of S aureus has cytolytic activity respectively. This antigen has been received the most attention since it is a major virulence factor in pathogenesis of staphylococcal mastitis. Thus, alpha toxin has been focused as potential candidate of vaccine to minimize mastitis in cows. The purpose of this study was to develop a simple, efficient production and purification methods of sufficient amount of alpha toxin antigen from S aureus. Alpha toxin production measured by hemolytic activity was the highest at 18 hrs postinoculation in yeast extract culture medium supplemented with thiamine, nicotinic acid and casamino acid. Alpha toxin was purified by ammonium sulfate precipitation (65%) and ultrafiltration. Molecular weight of the toxin was 33 kDa in the analysis with SDS-PAGE. Conclusionally, when alpha toxin was included in the vaccine, the optimal harvest time of alpha toxin was at 18 hrs after inoculation in yeast extract medium supplemented with thiamine and nicotinic acid.

• 대한수의학회지
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• 제27권2호
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• pp.185-189
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• 1987

The number of splenic lymphocyte, serum prostaglandin $E_2$ level and natural killer cell activity were assayed after single whole body irradiation of a sublethal dose of $^{60}Co-{\gamma}$ ray to C57BL/6J mice. With a view to knowing the relationships between radiation induced prostaglandin $E_2$ level and the normal natural killer cell activity after natural killer cell-target cell conjugation, The change of normal natural killer cell activity were measured by administration of prostaglandin $E_2$ containing serum from irradiated mice. The results were summarized as follows; 1. The total number of splenic lymphocyte was significantly decreased by irradiation and the number was not affected by indometacin, prostaglandin synthesis inhibitor, treatment. 2. Serum prostaglandin $E_2$ level was increased in irradiated mice, but indometacin treated mice group showed low level of prostaglandin $E_2$. 3. In the case of irradiated mice, natural killer cell activity was not shown any difference between irradiated group and indometacin combined group. But when natural killer cell-target cell conjugations were exposed to the serum of each group during cytotoxic activity assay, whereas the normal natural killer cell activity was significantly decreased by treatment of serum from irradiated mice, the activity was not changed by treatment of indometacin pretreated mice serum. This result indicated that the prostaglandin $E_2$ induced by the radiation inhibited the post-target binding cytolytic process of natural killer activity.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.1021-1026
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• 2003

Numerous secreted and cell-associated virulence factors have been proposed to account for the fulminating and destructive nature of Vibrio vulnificus infections. Among the putative virulence factors are an elastase, elastolytic protease, and a cytolytic hemolysin. Effects of the elastase on the hemolysin were assessed by evaluating changes of hemolytic activities either in the presence or absence of the protease. Although hemolytic activity in the culture supernatant was lowered by the purified elastase added in vitro, the cellular level of hemolytic activity was unaffected by the mutation of vvpE encoding the elastase. Growth kinetic studies revealed that hemolysin reached its maximum level in the exponential phase of growth, and the elastase appeared at the onset of the stationary phase. These results have provided insight into the regulation of virulence factors: temporally coordinate regulation of virulence factors is essential for the overall success of the pathogen during pathogenesis.

• Journal of Korean Neurosurgical Society
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• 제38권2호
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• pp.126-131
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• 2005

Objective : The choice of tumor antigen for dendritic cell[DC]-loading has still been an unresolved problem in the DC-based vaccine strategies against malignant gliomas that has not been found well-characterized tumor specific antigens. In this study, we compare tumor-specific T cell response induced by glioma apoptotic body[GAB]-pulsed DCs to response induced by glioma cell lysate-pulsed ones quantitatively. Methods : DCs generated in the presence of granulocyte macrophage-colony stimulating factor and interleukin[IL]-4 from peripheral blood mononuclear cells[PBMCs] of HLA-A2 positive healthy donors were cultured. Each GABs and glioma cell lysate generated from HLA-A2 positive T98G glioblastoma cells were co-incubated with DCs. $CD8^+$ T lymphocytes isolated from PBMCs of same donors were cultured in media containing IL-2 and either stimulated by GAB- or lysate-pulsed DCs three times at a weekly interval. The interferon[IFN]-${\gamma}$ concentrations of each cell culture supernate were measured by enzyme immunoassay technique. Cytolytic activity of the generated cytotoxic $CD8^+$ T cells either stimulated with GAB- or lysate-pulsed DCs was determined by a standard 4-h $^{51}Cr$-release assay. Results : IFN-${\gamma}$ production and cytolytic activity of effector T cells stimulated by GAB-pulsed DCs were significantly higher than those of T cells stimulated by lysate-pulsed ones. Conclusion : These results indicate the choice of antigen is a critical determinant in the induction of antitumor immunity against malignant glioma. Antigen preparations from GABs represent a promising alternative to glioma cell lysate in DC-based glioma vaccine strategies.

• Parasites, Hosts and Diseases
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• 제26권2호
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• pp.95-106
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• 1988

아메바의 cytolytic process가 주로 가수분해 효소 환성과 관계 깊다는 연구들이 70년대 후반부터 병원성 Entamoeba sp.와 Naegleria sp.에서 보고되었지만 Acanthamoeba sp.에서는 가수분해 효소 환성에 관한 연구는 찾아볼 수 없다. 본 연구에서는 병원성이 없는 것으로 알려진 Acanthamoeba royreba를 대조로 하여 병원성이 있는 A. culbertsonl이 가수분해 효소 활성도를 측정하고 이들을 비교하고자 하였다. A. culbertsoni를 마우스에 감염시켰더니 15일내에 마우스 모두가 사망하였으며, 평균 생존기간은 8.5일이었고, 아베바성 수막뇌염으로 사망했음을 알 수 있었다. 반면에 A. royreba를 감염시킨 마우스에서는 수막뇌염이 발생되지 않았다. CGV배지에서 두 종(種) 아메바를 배양하여 아메바 추출물 및 배양액에서 가수분해 효소의 환성을 측정한 결과 A. rcyreba에 비해 A. culbertsoni 세포의 추출물 및 배양액에서 현저히 활성도가 높은 가수분해 효소는 acid phosphatase, p-N-acetyl galactosaminidase, β-N-acetyl glucosaminidase, α-mannosidase, neutral proteinase, acid proteinase였다. 표적 세포인 CHO 세포에 혼합한 A. culbertsoni는 대조군에 비해 강한 세포독성을 나타내었고 CHO 세포와의 혼합후 48시간 후 80%, 72시간후 95% 이상의 CHO 세포가 사멸하는 것을 알 수 있었다. 반면에 A. royreba를 혼합하였을 때는 별다른 세포독성을 나타나지 않았다. CHO 세포에 혼합한 A. tulbgrtsoni이 가수분해 효소 활성도를 경과 시간별로 측정하였던 바 CGV 배지에서 배 양시간이 지남에 따라 아메바내보다 그 배양액에서 더 높은 효소 활성도를 나타내었던 acid phosphatase, β-N·acetyl galactosaminidase, β-N·acetyl glucosaminidase, α-mannosidase, acid proteinase는 혼합 120시간 동안 아메바내에서 더 높은 효소 활성도를 나타내었으며, neutral proteinase의 활성도는 경과시간이 지남에 따라 아메바내에서는 일정하였지만 그 배양액인 EBSS용액내에서는 점점 높아짐을 알 수 있었다. 이상의 성적으로 보아 마우스에서 수막뇌염을 일으키는 A. cuzbertsoni는 비 병원성인 A. reyreba와 비교할 때 여러 종류 가수분해 효소들의 활성도에 현저한 차이를 나타내고 있음을 알 수 있었다. 또한 표적세포인 CHO세포에 대한 A. cuzbertsoni의 세포독성은 강함을 알 수 있었고, 이 때 몇 종류 가수분해 효소들의 환성도도 높게 나타났으며, 이러한 소견이 A. culbertsoni의 병원성과 관련이 있을 것으로 추측되었다.

• 대한한방내과학회지
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• 제20권1호
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• pp.133-142
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• 1999

To clarifiy the effects of Scolopendrae corpus(S-C) on turmor promotion in two-stage carcinogenesis in mice was investigated. In vivo system, S-C were seen to gave an inhibitory activity on TPA-induced mouse ear edema. In addition, the S-C were proved to have antitumor-promoting activity in two-stage mouse skin carcinogenesis induced by DMBA and two-stage mouse lung carcinogenesis induced by 4-NQO as a initiator plus TPA and glycerol as a promoter. Moreover, S-C significantly exhibited an cytolytic effect in $HepG_2$ cells and showed significant antitumor activity against Sarcoma-180 bearing mice by oral administration. These results suggest that S-C could be effective in adjuvant chemotherapy for human cancer.

• IMMUNE NETWORK
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• 제10권5호
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• pp.153-163
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• 2010

Background: In addition to TCR and costimulatory signals, cytokine signals are required for the differentiation of activated CD8 T cells into memory T cells and their survival. Previously, we have shown that IL-12 priming during initial antigenic stimulation significantly enhanced the survival of activated CD8 T cells and increased the memory cell population. In the present study, we analyzed the mechanisms by which IL-12 priming contributes to activation and survival of CD8 T cells. Methods: We observed dramatically decreased expression of CD43 in activated CD8 T cells by IL-12 priming. We purified $CD43^{lo}$ and $CD43^{hi}$ cells after IL-12 priming and analyzed the function and survival of each population both in vivo and in vitro. Results: Compared to $CD43^{hi}$ effector cells, $CD43^{lo}$ effector CD8 T cells exhibited reduced cytolytic activity and lower granzyme B expression but showed increased survival. $CD43^{lo}$ effector CD8 T cells also showed increased in vivo expansion after adoptive transfer and antigen challenge. The enhanced survival of $CD43^{lo}$ CD8 T cells was also partly associated with CD62L expression. Conclusion: We suggest that CD43 expression regulated by IL-12 priming plays an important role in differentiation and survival of CD8 T cells.